Video Watermarking via Time-Varying Quantization Parameters

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Solution Overview

Problem

Existing video watermarking technologies require significant processing resources and dedicated hardware, making them impractical for implementation in consumer devices like digital video recorders (DVRs) without hardware modification.

Innovation Solution

A method of video watermarking that varies encoding parameters, such as quantization factors, over time to embed a watermark, allowing for robust watermarking without requiring hardware modifications, using existing DVRs' modest processing resources and software updates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If dedicated hardware or fast processors are used for video watermarking, then watermarking robustness and detection accuracy are improved, but device complexity and cost increase significantly

Engineering Contradiction:

Improvewatermark detection accuracyVSAvoidhardware complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces dedicated hardware watermarking systems with software-based watermarking that operates on standard video encoders. Instead of using specialized hardware circuits for watermark embedding and detection, the invention uses software algorithms that manipulate video encoding parameters (quantization matrices, bitrate, frame rate) to embed watermarks, making the system compatible with consumer-grade devices without additional hardware.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent makes the video encoder serve dual purposes: both standard video compression and watermark embedding. By controlling encoding parameters during normal video encoding operations, the system embeds watermarks without requiring a separate watermarking hardware module, thus achieving multi-functionality with existing components.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Ease of manufacture

If video watermarking is performed on baseband uncompressed signals, then watermark embedding simplicity is improved, but processing power requirements increase significantly

Engineering Contradiction:

Improvewatermark embedding simplicityVSAvoidprocessing power

Core Design Contradiction:

Ease of manufactureVSPower

Solution Approach 1:

Instead of embedding watermarks in uncompressed baseband video and then compressing (which requires heavy processing), the patent inverts the approach by embedding watermarks during the compression process itself. The watermark is embedded by manipulating encoding parameters in the compressed domain, which reduces processing requirements while maintaining watermark integrity.

Inventive Principle:

Principle #13The other way round (Inversion)

3Power

If video watermarking is performed on compressed video streams, then processing resource requirements are reduced, but watermark robustness against re-encoding attacks decreases

Engineering Contradiction:

Improveprocessing resourcesVSAvoidwatermark robustness

Core Design Contradiction:

PowerVSReliability

Solution Approach 1:

The patent embeds the watermark during the initial encoding process before any potential re-encoding attacks can occur. By controlling the encoding parameters (quantization matrices, bitrate, frame rate) during the first encoding pass, the watermark is embedded in a way that survives subsequent re-encoding operations, providing preliminary protection against future attacks.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses parameter-based watermarking where specific encoding parameters (quantization matrix values, bitrate adjustments, frame rate variations) are modified according to the watermark data. These parameter changes create a robust watermark that is embedded in the compression process itself, making it resistant to re-encoding attacks while requiring minimal processing resources.

Inventive Principle:

Principle #35Parameter changes

4Device complexity

If existing DVR hardware is used without modification, then device cost and complexity are minimized, but watermarking capability is lost

Engineering Contradiction:

Improvehardware modification requirementVSAvoidwatermarking capability

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent replaces the need for hardware modification with software-based watermarking that utilizes the existing video encoding functionality in DVRs. By controlling the encoder's parameters through software, the system gains watermarking capability without any hardware changes, maintaining device simplicity while adding functionality.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS9253485B2Video watermarking

Publication Date: 2016.02.02 NAGRAVISION SA

AI summary

A method of watermarking a video signal includes encoding the video signal using at least one encoding parameter that is time-varied according to a watermarking pattern. The parameter affects information lost while encoding the signal. The parameter may be a quantization factor corresponding to a particular coefficient of an encoding transform. The parameter may be an element of a quantization matrix corresponding to a particular coefficient in a block DCT transform. The method may be implemented in devices with limited processing resources by means of a software update. The method enables the devices to imprint an encoded signal with a robust watermark, which may survive subsequent decompression and recompression. Alternatively, a video signal may be watermarked by modifying a magnitude of a non-dc spatial frequency component in a manner which varies with time according to a watermarking pattern. Corresponding watermark detection methods and watermarking devices also are disclosed.